Relnote Human Interface - HP 340 Series Service Manual

Input Devices
Two types of input devices are used:
• RS-232 controller on processor board with supported HP terminal.
• HP-HIL keyboard circuits on processor board.
Note that if a rernote terminal is present in a system, both the HP-IL and RS-232 controllers
will both be enabled.
If a keyboard controller fails, then it is considered to be "not present" and no keyboard failed
Inessage will be displayed. In this case, the RS-232 interface would be the only other input
device providing the remote bit is set and a terminal is used. The Boot ROM always tests a
device before choosing it as the console input device.
If no output device is present, but a keyboard is present, then that keyboard will still act as
the console input device. Similarly, if no input device is present, but video circuits are present,
then the video circuit will still act as the console output device. If neither an input device nor
an output device is present, the Boot ROM will go ahead and automatically boot the default
operating systenls as long as no errors are discovered during self test (see the section on Self-Test
for more details).
Rernote terminals as consoles are discussed in more detail in the next section.
Remote Human Interface
Very early in the power-up sequence, a search is made for a RS-232 interface with its "remote"
bit set. If one is found, it becomes the remote human interface. Note that the RS-232 appears
as an HP 98644 card and will be treated as such by the Boot ROM.
To indicate that a rernote human interface has been found (at, for example, select code 9), the
first line of the display will show:
Remote Interface at 9
After this point the display will not change until a system is booted. The keyboard electronics
will work just as they would if there were no remote console (see previous section for details).
Using a Remote Interface
To use the remote interface, an 80 wide terminal with at least 24 lines that accepts the following
HP standard terrninal escape sequences is required:
Key Sequence Function
Escape H Escape
J
To Clear Screen and reset cursor
Escape &aDDY To Move Cursor to Row DD
Escape &aDDC To Move Cursor to Column DD
The Boot ROM will use the baud rate, pacing, and line characteristics of the RS-232 interface.
Boot ROM Functions
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